An attempt was made to determine the effects of selenium and vitamin E supplementation on thyroid hormones in lambs. Sixteen Akkaraman lambs were used and divided equally into four groups. One group was used as a control. Second group was fed with selenium (sodium selenite, 0.3 mg kg(-1) feed). Third group was fed with vitamin E (DL-alpha tocopheryl acetate, 250 mg-1 feed) and fourth group was fed with selenium (sodium selenite, 0.3 mg/ kg(-1) feed) + vitamin E (DL-alpha tocopheryl acetate, 250 mg kg(-1) feed) supplemented diet. Serum selenium, vitamin E and plasma thyroxine (T-4) and tri-ioda-thronine (T-3) were measured at 1st, 5th, 10th weeks.